Monstera deliciosa, also called the split-leaf philodendron and Swiss cheese plant, is a popular houseplant with distinctive split and perforated leaves. This viney plant is easy to maintain, but even the hardy Monstera can develop problems such as brown spotting.
A number of factors may cause brown spotting, including bacterial diseases, mites or too little water. Very moist conditions can encourage fungi to flourish on Monstera leaves.
Bacterial and fungal infections on Monstera tend to take the form of brown to black spots with a yellow halo around them. Brown spots on the underside of leaves indicate red spider mites. A plant that's not getting enough water will often have yellow lower leaves with some brown spotting.
Treatment of brown spots depends on the cause. For problems caused by under-watering, simply water more frequently or increase humidity. Treat fungal infections by removing damaged leaves and applying mild fungicide. Use insecticidal soaps to kill spider mites, and treat bacterial spotting by pruning infected leaves.